Adsorptive removal of azo dyes from aqueous solutions by natural bentonite under static and dynamic flow conditions

Abstract

This work reports new findings on the physisorption of Foron Blue 291 on natural bentonite under both static and dynamic flow conditions of the aqueous solution that may prove important when using the adsorption technique for wastewater treatment. The quantity of dye retained by the solid matrix under both ideal exchange conditions between dyes and adsorbents given in a batch reactor and a pulse injection of dissolved azo dye in a soil column composed of a mixture of mean grain-sized sand and bentonite at different flow rates and at various mass fractions of bentonite was studied. Column experiments involving the use of a non-reactive tracer (Fluorescein) were performed to examine hydrodynamic behaviours of the clay/sand mixture studied. It is shown that advective-dispersive transport across a clay/sand mixture may be characterized by a double porosity medium. The results obtained on the reactive transport of Foron Blue 291 underscore that Foron Blue 291 adsorption depends heavily on the mass fraction of clay in a clay/sand mixture. With a clay mass fraction of 30 %, 77 % of the dissolved Foron Blue 291 mass was irreversibly removed by the adsorbent. At low flow rates, removal ratios obtained from the dynamic reactive system were similar to those obtained through previous static reactor experiments.

Pollutant Dissipation at the Sediment‐Water Interface: A Robust Discrete Continuum Numerical Model and Recirculating Laboratory Experiments

“…Two configurations have been investigated with either pollutant originating from the sediment or the overlying water. Saline solution (NaCl) was used as a pollutant for the conservative tracer and the dye FB291 (CAS Number: 56548-64-2) was used as a strongly sorptive molecule (Berez et al, 2016). The combination of tracers with different sorptive properties allowed to distinguish between organic pollutant transport and phase partitioning in lab-scale constructed wetlands (Fernandez-Pascual et al, 2020).…”

Surface Modification of Bentonite with Polymer Brushes and Its Application as an Efficient Adsorbent for the Removal of Hazardous Dye Orange I

“…Due to it being naturally occurring and easily available, bentonite (Bent) has attracted significant interest as an adsorbent. Berez et al reported the wastewater treatment by the physisorption of Foron Blue 291 on natural bentonite under both static and dynamic flow conditions of the aqueous solution [ 36 ], while the poor dispersibility of the natural Bent limited its adsorption property. In order to improve its dispersibility, some special functional groups should be modified onto a Bent surface to enhance the adsorption amount of the natural Bent.…”

Crosslinked Egg White as Eco‐Friendly, Reusable, and Cost‐Effective Biosorbent for Rapid Removal of Indigo Carmine

“…Dyes are widely used in different industries such as textile, pigment, cosmetics, food stuffs, etc., and more than 8000 chemically different types of dyes are employed in these industries . It is estimated that color production levels are about 800 000 tons/year . Most dyes are synthetic and complex organic chemicals.…”

“…[1,2] It is estimated that color production levels are about 800 000 tons/year. [3] Most dyes are synthetic and complex organic chemicals. High amount of dye in effluents affect the photosynthetic action of plants.…”